Diesel fuel filter system

Abstract

A heater system for a diesel fuel filter comprises a housing, a self-regulating electrical resistance heater element of positive temperature coefficient of resistivity arranged in heat-transfer relation to thermally conducting components to form a heater means, the heater means being mounted within the housing so that diesel fuel passes directly over and around the various thermally conducting components of the heater means to elevate the temperature of the fuel as it passes to the filter to deter clogging of the filter by paraffin or other fuel components which may solidify in the fuel at lower temperatures, and electrically conducting means which extend from the housing in sealed relation to the housing for electrically connecting the heater means to a source of electrical power.

We claim: 
     
       1. A heater system for a diesel fuel filter comprising a housing means having a chamber and having an inlet and an outlet for the chamber for permitting diesel fuel to flow therethrough to a diesel fuel filter, thermally conducting plate means, having at least one opening therein, at least one self-regulating ceramic resistance heater disc element of a material of positive temperature coefficient of resistivity secured in thermally and electrically conducting heat-transfer relation to said thermally conducting plate means so that the element and plate means form a heater means, said heater means being mounted within said housing chamber at a location intermediate the inlet and outlet thereof so that the flow of diesel fuel through the chamber between the inlet and outlet to a diesel fuel filter normally passes the fuel directly over and around the ceramic heater disc element and through said opening in said thermally conducting plate means to accomplish rapid heat-transfer to the fuel as the fuel passes toward a filter, thereby to deter clogging of such a filter by paraffin or other fuel components which may solidify in the fuel at lower temperatures, and electrically conducting means extending from the housing chamber for electrically connecting the heater means to a source of electrical power. 
     
     
       2. A heater system as set forth in claim 1 wherein the housing chamber has an aperture therein, the heater disc element has ohmic contact means on opposite sides thereof and has the contact means on one side thereof secured in electrically and thermally conductive relation to said plate means in heat-transfer relation thereto, and the electrically conducting means comprises terminal means extending from the housing through said aperture and means for sealing said terminal means in said housing aperture, the terminal means being arranged in the chamber so that the flow of diesel fuel through the chamber between the inlet and outlet to a fuel filter normally passes the fuel directly over and around portions of the terminal means in heat-transfer relation thereto.